netwizxrd

Industry-standard, vendor-neutral network intelligence tools, built by a principal network engineer.

Tools

Live

Subnet Wizard

IPv4 and IPv6 subnet calculator built for network engineers — network and broadcast addresses, wildcard masks for ACLs, usable host ranges, subnet splitting, and multi-vendor configuration generation.

subnetwizard.com

In development

Config Comparator

Compares two device configurations by meaning rather than by text. Configuration is normalized into a vendor-neutral model, so reordered statements and equivalent syntax stop registering as changes — and real divergence stops hiding among them.

See the preview

Config Comparator

Semantic comparison, not a text diff.

Comparison

1 high 1 medium 1 expected variance

edge-01.set Side A

1set groups CORE-UPLINK interfaces <ge-*> mtu 9192

2set apply-groups CORE-UPLINK

3set interfaces ge-0/0/0 description "to core-a xe-1/0/3"

4~set interfaces ge-0/0/0 mtu 9192

5set interfaces ge-0/0/0 unit 0 family inet address 10.11.12.1/24

6≈set interfaces lo0 unit 0 family inet address 192.0.2.1/32

7set policy-options prefix-list BOGONS 10.0.0.0/8

8set policy-options prefix-list BOGONS 192.168.0.0/16

9−set policy-options policy-statement EBGP-IN term REJECT-BOGONS from prefix-list BOGONS

10−set policy-options policy-statement EBGP-IN term REJECT-BOGONS then reject

11set policy-options policy-statement EBGP-IN term ACCEPT-CUST from prefix-list CUST-NETS

12set policy-options policy-statement EBGP-IN term ACCEPT-CUST then accept

13set protocols bgp group EBGP import EBGP-IN

14set protocols ospf area 0.0.0.0 interface ge-0/0/0.0

edge-02.set Side B

1set groups CORE-UPLINK interfaces <ge-*> mtu 9192

2set apply-groups CORE-UPLINK

3set interfaces ge-0/0/0 description "to core-a xe-1/0/3"

4~set interfaces ge-0/0/0 mtu 1500

5set interfaces ge-0/0/0 unit 0 family inet address 10.11.12.2/24

6≈set interfaces lo0 unit 0 family inet address 192.0.2.2/32

7set policy-options prefix-list BOGONS 10.0.0.0/8

8set policy-options prefix-list BOGONS 192.168.0.0/16

−term REJECT-BOGONS — not present

9set policy-options policy-statement EBGP-IN term ACCEPT-CUST from prefix-list CUST-NETS

10set policy-options policy-statement EBGP-IN term ACCEPT-CUST then accept

11set protocols bgp group EBGP import EBGP-IN

12set protocols ospf area 0.0.0.0 interface ge-0/0/0.0

− removed ~ modified ≈ semantically equivalent

High route_policy · EBGP-IN f-4a19c7

Import policy term REJECT-BOGONS removed on edge-02.

before_state

term REJECT-BOGONS {
    from prefix-list BOGONS;
    then reject;
}

after_state absent

edge-02 accepts bogon prefixes from the eBGP peer that edge-01 rejects. Filtering is asymmetric across the pair, and the looser side is the one that decides what enters the table.

dependencies prefix-list BOGONS policy EBGP-IN bgp group EBGP

change_typeremoved

intent_classificationsuspicious_divergence

confidence 0.96

recommended_validation show route receive-protocol bgp <peer> 10.0.0.0/8

Medium interface · ge-0/0/0 f-9be302

MTU reduced from 9192 to 1500 on a core uplink.

before_statemtu 9192

after_statemtu 1500

OSPF can stall in ExStart/Exchange, and large frames blackhole in one direction while small packets pass — the symptom presents as intermittent rather than as a down link.

dependencies ge-0/0/0.0 ospf area 0.0.0.0

change_typemodified

intent_classificationsuspicious_divergence

confidence 0.88

recommended_validation show ospf neighbor | match ge-0/0/0

Info ip_address_assignment · lo0.0 f-1c77e0

Loopback addressing differs per node.

before_state192.0.2.1/32

after_state192.0.2.2/32

No action. Per-node addressing is the expected pattern across a pair; it is reported so it is accounted for rather than silently dropped.

dependencies router-id bgp local-address

change_typemodified

intent_classificationexpected_variance

confidence 0.99

recommended_validation None required.